• Journal of the Korean Geographical Society
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• v.30 no.1
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• pp.35-56
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• 1995

During the last two decades, Korea has achieved remarkable economic growth. In this process the nation has become urbanized and industrialized. But we have also encountered widening regional disparity, housing shortage of larger cities, transportation congestion, environmental pollution and many other problems. Rapid increasing urbanization and continuous migration toward Seoul since the late 1960s have been one of the major concerns of government. Government has sought ways to moderate the population increase in Seoul. The regulation which include new town development near Seoul and dispersion strategies of higher education and other administration and living facilities outside of Seoul havemade a great expansion of the spatial influence of Seoul city. Seoul metropolitan reaion has evolved as the most powerful center of political and economical spaces. Generally within a metropolitan region, there exists a growing mutual interdependence economically, as well as socially between a central city and its surrounding area. Seoul metropolitan region manifests itself not only as a coherent system of urbanized regions, but also as an integral part of the daily urban system. The surrounding Gyunggi province and Seoul city become closely linked both economically and functionally, constituting true functlonai urban system. This study is primarily undertaken with the purpose of delineation of the sphere of influence of Seoul city in 1990. At the time of 1985, Seoul metropolitan region was delineated according to the result of the study which was performed by Korea Research Institute for Human Settlements. Afterward, the rapid speed of metropolitanization process with dramatic increase in mobility through the provision of wider transportation system across the Capital region have evolved, resulting in the great expansion of the spatial influence of Seoul city. So this study examines the expanded area of Seoul metropolitan regin during the period of 1985-90. In order to delineate Seoul metropolitan region, the indices of urbanization and functional linkage are selected. Variables included in the measurement of the urbanization level are agricultural structure, population characteristics, manufacturing and service industries, and cultural aspects such as newspaper circulation, the ratio of car ownership and piped water supply. Variables included in the measurement of functional linkage are commuting, shopping pattern, centralized service such as medical facilities and trade of agricultural products. The standardization method and factor analysis are employed in making the delineation of Seoul metropolitan region. According to the result of this study, 2 cities, 8 Eups and 46 Myuns are included Seoul metropolitan region in 1990. If we compare this delineated area in 1990 to that of 1985, we can find the distinctive pattern of expanded axes according to the main transportation routes such as Seoul-Suweon, Seoul-Gwangju, Seoul-Incheon. In 199O, all the Gyunggi province, except a few Myuns located at the north and northwest part of Gyunggi province, are included in Seoul metropolitan region. Furthermore, this study attempts to the analysis of regional structure of Seoul metropolitan region according to the functional characteristics of each city and Gun. Variables included in this analysis are the new residential function, manufacturing function, service function, education and infermation function, public facility function and agricultural function. Factor analysis and cluster analysis are employed in making regionalization. Seoul metropolitan reaion is subdivided into four subregions which reflect different functional specialization. The first group is the specialized region of newly formed residential function. The second group is the specialized reaion of manufacturing function. The third group is the specialized region of service function. And the fourth group has little specialized in terms of manufacturing, service, and residential function. But this region has some potentiality of development when Seoul metropolitan region grow continuously. Seoul metropolitan region accounted for 43% of national population, despite 11.8% of national land size in 1990. Although Seoul metropolitan region enjoys important agglomeration economies, it also has huge social cost in the form of transportation congestion, housing shortage, rapid increase of land value, environment pollution, and etc. Efficient metropolitan plan making is a vital element in promoting Seoul's economic development and providing high quality living environment at low cost. In the light of the result of this study, the outer ring of Seoul metropolitan region, especially northeastern part, are underdeveloped compared to overdeveloped southwestern area. It is needed to develop the guidelines for the implement of the growth control and management plan, inducing more balanced development for whole Seoul metropolitan reaion.

• Food Science and Preservation
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• v.17 no.3
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• pp.398-404
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• 2010

It is known that onions, or bioactive compounds therein, providehealth benefits. The present study was designed to investigate whether a concentrated onion extract lowered blood lipid levels in rats fed a high-fat diet. Initially, male Sprague-Dawley rats were housed singly in an environment in which temperature and light duration were controlled, and had free access to a nutritionally adequate AIN-93G diet and deionized water. After an acclimatization period, rats were weight-matched and assigned to one of the following five groups: 1) a control group, fed the AIN-93G diet mixed with 10% (w/v) lard and 0.7% (w/v) cholesterol to induce hyperlipidemia (control); 2) three experimental groups, fed the AIN-93G diet mixed with a high-fat source plus concentrated onion extract at three different levels (termed the low-dose, medium-dose, and high-dose groups); and, 3) a placebo group, fed the AIN-93G diet with fats plus the same concentrated extract but devoid of onion-derived material. All five groups freely ingested their respective diets over 6 weeks. At 0, 3, and 6 weeks, blood samples were collected from the orbital sinus following overnight food deprivation. At 6 weeks, livers were collected. Both control and experimental groups continually gained body weight throughout the study. No significant differencein body weight gain was observed among groups. However, the serum concentrations of triglycerides, total cholesterol, and non HDL-cholesterol were significantly reduced by ingestion of concentrated onion extract. Also, the hepatic levels of total lipids and total fatty acids, especially C18:1 (oleic acid), were significantly decreased in rats fed a high level of concentrated onion extract, compared with the control and placebo groups. These results provide clear evidence that ingestion of a concentrated onion extract has a profound inhibitory effect on serum lipid levels in rats fed a high-fat diet. Our findings indicate that a concentrated onion extract may be used to alleviate hyperlipidemia by lowering serum cholesterol and triglyceride levels.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.8
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• pp.1200-1205
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• 2015

Medical foods are enteral nutrition for patients, but they cause maladaptation symptoms like diarrhea. Although the cause of diarrhea remains unknown, some studies have indicated that the cause of diarrhea is fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP). This is a consideration for medical foods since they are easily fermented by intestinal bacterial. In this study, we estimated the FODMAP contents of commercial medical foods and carbohydrate ingredients. We measured the concentrations of FODMAP in 13 types of different medical foods and five types of carbohydrate ingredients by using high performance liquid chromatography with an evaporative light scattering detector (HPLC-ELSD). The limits of detection of FODMAP were fructose, 0.002; lactose, 0.010; raffinose, 0.003; stachyose, 0.032; 1-kestose, 0.005; nystose, 0.012; and 1-fructofuranosylnystose, 0.003 mg/kg. Limits of quantitation of FODMAP were fructose, 0.008; lactose, 0.033; raffinose, 0.009; stachyose, 0.107; 1-kestose, 0.015; nystose, 0.042; and 1-fructofuranosylnystose, 0.011 mg/kg, respectively. Concentration of FODMAP ranged from 0.428~2.968 g/200 mL. Concentrations of carbohydrate ingredients in FODMAP were chicory fiber, 278.423; soy fiber, 27.467; indigestible maltodextrin, 52.384; maltodextrin (DE10~15), 32.973; and maltodextrin (DE15~20), 50.043 g/kg. Contents of carbohydrates were 19.0~41.0 g/200 mL in commercial medical foods. We expected a correlation between contents of carbohydrates and FODMAP, as carbohydrates included FODMAP. However, we detected a low correlation (r=0.55). Since most commercial medical foods have a similar carbohydrate ingredients and nutritional values, the difference between products was determined by FODMAP contents of carbohydrate ingredients. In this study, we analyzed FODMAP contents of commercial medical foods and carbohydrate ingredients. These results are expected to be utilized as basic data for product development and minimizing maladaptation of medical foods.

• The korean journal of orthodontics
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• v.29 no.5 s.76
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• pp.613-625
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• 1999

The purpose of this study was to compare the bracket shear bond strengths of the crystal growth solutions with those of the $37\%$ phosphric acid etch technique. The 4 crystal growth solutions were made experimentally in the lab, that is, (1) $30\%$ polyacrylic acid solution containing 0.3 M sulfuric acid (ES 1), (2) $30\%$ polyacrylic acid solution containing 0.6M sulfuric acid (ES 2), (3) $30\%$ polyacrylic acid solution containing 0.3 M sulfuric acid and 0.6 M lithium sulfate(ES 3), and (4) $30\%$ polyacrlic acid solution containing 0.3 M sulfuric acid and $5\%$ phosphoric acid(ES4). The $37\%$ phosphoric acid solution used as a control. Bovine lower incisor tooth enamel was treated by the above solutions for 60 sec, washed out for 20 sec with slow water stream, and bonded lower anterior edgewise bracket with the light curing orthodontic composite resin adhesives. The teeth bonded brackets were stored in the distilled water at room temperature for 24 h, and followed to test the bracket shear bond strength. The acid etch technque showed 177.6 kg/$cm^2$ of mean shear bond strength which was the highest among the enamel treatment solutions. ES 1 shown 58.4 kg/$cm^2$ of mean shear bond strength and that of ES 4 showed 66.5 kg/$cm^2$. There was no significant difference between the two(p>0.05). ES2 showed 110.6kg/$cm^2$ of mean shear bond strength which was $62.3\%$ of that of acid etch technique. ES 3 showed 131.1 kg/$cm^2$ of mean shear bond strength which was the highest among experimental crystal growth solutions and which was $74\%$ of that of acid etch technique. The shear bond strengths of the crystal growth solutions were significantly lower that that of acid etch technique(p<0.05). The results sugest that although bracket shear bond strength of $30\%$ polyacrylic acid solution containing 0.3M sulfuric acid and 0.6 M lithium sulfate were showed the highest, it is low for the clinical application of this solution.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.30-37
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• 2009

Early enamel caries is commonly remineralized by the patient‘s improved oral hygiene or fluoridation, however the result is clinically unreliable. As an alternative, we tried to seal the lesions with low-viscosity light-curing resin. The aim of the present study was to search the proper methods of the adequate pretreatment prior to applying adhesive resin on natural proximal caries lesions. Thirty nine extracted deciduous molar teeth showing proximal early caries lesion were used for this study. They were divided into 5 groups : Group 1; only carefully cleaned with water, group 2; etched with 15% HCl for 15s, group 3; etched with 35% phosphoric acid for 15s, group 4; etched with 35% phosphoric acid for 30s, and group 5; cleaned with 0.5% NaOCl. Following results were obtained by evaluating with SEM and CLSM after applied with adhesive resin. 1. As a result of SEM evaluation, group 2 showed clearly removed surface layer, group 3,4 showed partially removed surface layer irregularly, group 5 showed slightly removed surface layer. 2. Group 2 showed the deepest infiltration depth, followed by group 4, group 3, group 5, group 1 and besides group 5, other groups showed significantly deep infiltration depth. (p < 0.01) In conclusion, the best methods of the adequate pretreatment on natural proximal caries lesion for deep infiltration of adhesive resin was to etch with 15% HCl for 15s.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.593-601
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• 2016

This study was carried out to establish an effective marketing strategy based on Importance-Performance Analysis (IPA) of rice-convenience foods. IPA is one of the most efficient and simple methods to evaluate product quality. Data were collected from 652 people (320 males and 332 females) and analyzed by SPSS 19.0. Subjects consumed rice-convenience foods as a snack substitute (19.3%), breakfast (20.7%), lunch (37.4%), dinner (15.2%), and late-night meal (7.4%). The purpose for consumption of rice-convenience foods were as follows: light meal (34.8%), lack of time to prepare meal (42.2%), favorite restaurant is not nearby (2.3%), save money (3.4%), and outdoor activities (9.7%). All attributes about rice-convenience foods were categorized into intrinsic property and extrinsic property. As a result of factor analysis, health, sensibility, and diversity factors were extracted from intrinsic property. In addition, dependence and appearance factors were drawn from extrinsic property. In analyzing the differences between importance and performance, there were significant differences; 16 items in the intrinsic property (P<0.01), and 10 items in the extrinsic property (P<0.001). The IPA matrix is composed of four quadrants, and each represents different strategies; the first, 'keep up the good work', the second, 'possible overkill', the third, 'low priority for management', and the fourth, 'concentrate management'. As a result, factors of rice-convenience foods positioned in the fourth quadrant were 'safety (from food additives, etc.)' and 'price' in the intrinsic property and 'nutrition label' and 'safety of packaging material' in the extrinsic property. They need to be improved immediately. In this study, rice-convenience food factors for continuous maintenance and concentrative improvement were compared by IPA. Based upon the results of this study, it is necessary to develop methods to make efficient use of limited resources and practical marketing strategies.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.10
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• pp.1397-1405
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• 2009

This study was to investigate food components of Bigum spinach growing in Jeonnam Shinan. The samples used in this study were Pohang spinach of inland and jo-saeng, chung-saeng, man-saeng, chungman-saeng spinach of Bigum located on Jeonnam Shinan. We analyzed proximate composition, mineral content, germanium, organic acid, free sugar, vitamin A, C, and E contents. We conducted the sensory evaluation after blanching and color changes of before and after blanching of 5 kinds of spinach. The results were as follows: moisture and ash contents were significantly higher in Pohang spinach than Bigum spinach. Crude protein, carbohydrates and crude fiber contents were higher in Bigum spinach than Pohang spinach. In mineral contents, potassium and zinc contents were higher in Pohang spinach than Bigum spinach whereas calcium, iron, magnesium, manganese, sodium contents were higher in Bigum spinach than Pohang spinach. Germanium contents was 14.06$\sim$27.16 ppb in Bigum spinach whereas not detected in Pohang spinach. In organic acid contents, man-saeng and jo-saeng of Bigum spinach were high in oxalic acid, citric acid, malic acid and formic acid contents. Succinic acid and acetic acid contents were high in Pohang spinach. Almost all free sugars were higher in Bigum spinach, especially jo-saeng and man-saeng, than Pohang spinach except lactose. Vitamin A contents was similar with Pohang and Bigum spinach except chung-saeng but vitamin C and E contents were higher in Bigum spinach than Pohang spinach. Color L (light) after blanching was significantly higher in chungman-saeng than other spinaches. Color a (redness) was significantly lower in chung-saeng and man-saeng than others and chungman-saeng was significantly higher than others. Color b (yellowness) was low in man-saeng and high in jo-saeng of Bigum spinach. In case of sensory properties after blanching, taste, sweet, overall preference were significant higher in Bigum spinach except chung-saeng than Pohang spinach.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.207-219
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• 2016

Incandescent (INC) lamps have been commonly used to promote flowering of long-day (LD) plants during short-day (SD) seasons, but production of INC lamps has been prohibited due to their low energy efficiency. One of the light sources replacing INC lamps is a compact fluorescent lamp (CFL). This study was carried out to compare the flowering and morphological responses of LD annuals grown in a controlled environment greenhouse at $20^{\circ}C$ with a truncated 9-h SD and a 2- or 4-h night interruption (NI) or 6-h day extension (DE) provided by lighting from INC lamps, CFLs, or a combination of the two (INC + CFLs), in which red (R) to far-red (FR) ratios were 0.60, 8.46, and 0.91, respectively, and their PPFDs were $2.3{\pm}0.3{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. After 12 weeks of treatment, $Petunia{\times}hybrida$ 'Wave Purple' plants did not flower under the SD photoperiod whereas 100% flowered under all of the LD treatments. Flowering was more rapid under the INC or INC + CFL lighting treatments compared to CFL and DE, and 4-h NI enhanced flowering compared to 2-h NI. In addition, plants under DE and 4h-NI generally flowered earlier than under 2-h NI. All petunia 'Single Dreams Red' plants flowered within 65 days after treatment, and flowering was hastened by some LD lighting regimens and lamp types. Plants under DE and 4h-NI generally flowered earlier than under 2-h NI INC or INC + CFL compared to FL, and flowering time under INC 6-h DE was earliest. In addition, INC lighting promoted stem elongation of both petunia cultivars. In both pansy (Viola${\times}wittrockiana$) 'Coiossus Yellow' and 'Delta Blue Blotch', LD treatments, especially using INC lamps, promoted flowering whereas the lighting period had little influence on days to flowering. Therefore, INC or INC + CFL with lower R:FR promoted flowering and stem extension and the promoting effect was larger with longer lighting periods. These results suggest that CFLs can be used to provide LDs to promote the flowering of petunia and pansy and to reduce stem elongation, although the promoting effect on flowering is sometimes less than that of INC lamps alone.

• Journal of Life Science
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• v.27 no.1
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• pp.15-22
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• 2017

Streptococcus mutans (S. mutans), which plays a major role in the etiology of human dental caries, is able to tolerate exposure to acid shock in addition to its acidogenicity. We investigated the effects of pH stress on membrane fluidity, activities and expression levels of F-ATPase, and proton permeability in S. mutans. Using 1,6-diphenyl-1,3,5-hexatriene, we observed membrane ordering at pH 4.8 and pH 8.8. The ordering effects were larger at pH 4.8 in cytoplasmic membranes isolated from S. mutans (CMSM). Increasing pH resulted in a decrease in the activities and expression levels of F-ATPase. The proton permeability was decreased at both acidic and alkaline pHs, and the lowest permeability was observed at pH 4.8. The lower permeability at pH 8.8 than pH 6.8 is likely to be caused by the decreased proton influx due to the decreased CMSM fluidity. In addition, it seems to be evident that extremely low permeability at pH 4.8 was caused by the decreased proton influx due to the decreased CMSM fluidity as well as the increased proton efflux due to the increased activity and expression level of F-ATPase. It is likely that CMSM fluidity and F-ATPase activity are two major key factors that determine proton permeability in S. mutans. We suggest that CMSM fluidity plays an important role in the determination of proton permeability, which sheds light on the possibility of using nonspecific membrane fluidizers, e.g., ethanol, for anti-caries purposes.

• Journal of Bio-Environment Control
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• v.25 no.2
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• pp.111-117
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• 2016

The objective of this study was to analyze the microclimate and the growth of tomato and lettuce in the greenhouses covered with spectrum conversion films using different phosphor particles sizes. Two spectrum conversion films using phosphor particles larger than $10{\mu}m$ (Micro-film) and smaller than 500 nm (Nano-film) in radius, and poly-ethylene (PE) film were used in double-layered greenhouses as outer coverings. PE films were used as inner coverings in all the greenhouses. Thickness of the films for inner and outer coverings was 0.06 mm. Tensile strength, elongation, and tearing resistance of the Micro- and Nano-films were not different from those of the PE film. Transmittances at a wavelength of 300-1100 nm were a little higher at the Micro-film and lower at the Nano-film than that of the PE film, respectively. Air temperatures at the Micro- and Nano-films were over $2^{\circ}C$ higher than at the PE film, but no significant difference was observed between the two light conversion films. The soil temperature at the Nano-film was $1.5^{\circ}C$ and $3^{\circ}C$ higher than at the Micro- and PE films, respectively. The yields of tomato at the Micro- and Nano-films were 12% and 14% higher than at the PE film, but no significant difference was observed between the two spectrum conversion films. The total soluble solid showed no significant differences among all the films. The yields of lettuces at the Micro- and Nano-films were 27% and 59% higher than at the PE film. Hunter's red (a) value of the lettuce leaf was the highest at the Nano-film. In this experiment, tomatoes requiring high irradiation were better at the Nano film, while lettuce requiring low irradiation better at the Micro film.